The present invention relates to an arrangement for coupling or connecting an air compressor to the driving shaft of an internal combustion engine that is used as the drive engine of a vehicle, wherein the air compressor supplies a pneumatic device; the invention also relates to a method of operating such an arrangement.
With vehicles that are common these days, and which have pneumatic devices, the air compressor is coupled directly with the driving shaft of the internal combustion engine via appropriate gearing arrangements.
The quantity of air delivered from the air compressor to the pneumatic device is regulated by excess pressure valves that are disposed in the pneumatic device in such a way that when a maximum pressure is exceeded, the excess air escapes via the indicated excess pressure valves.
Although such arrangements have a simple construction, they do not take into account the minimization of fuel consumption demanded these days, and in addition have the drawback that the characteristic, which results with the reciprocating piston air compressors that are used, of exerting a negative torque, after passing the upper dead center position, due to back expansion, leads to the lifting of the tooth surfaces of prearranged toothed-wheel gearings. This shifting of the tooth surfaces, in turn, is responsible for an extremely undesirable development of noise, and increases the wear of the gears that are involved.
Proceeding from the foregoing factors, it is an object of the present invention to provide an arrangement for coupling the air compressor to the driving shaft of an internal combustion engine that is used as the drive engine of a vehicle, whereby the arrangement minimizes the consumption of fuel of the internal combustion engine and transfers no negative torque. It is a further object of the invention to provide a method for operating the inventive arrangement.